http://www.berklix.com/~jhs/src/bsd/fixes/FreeBSD/src/gen/etc/services.ups-nut.REL=CURRENT.diff
By { 12.0-ALPHA8 & 12.1-RELEASE & 2018-11-06 13.0-CURRENT } 
etc/services had moved to usr.sbin/services_mkdb/services

*** old-13.0-RELEASE-p8/src/usr.sbin/services_mkdb/services    Tue Apr 12 15:36:27 2022
--- new-13.0-RELEASE-p8/src/usr.sbin/services_mkdb/services    Tue Apr 12 15:37:36 2022
***************
*** 1786,1791 ****
--- 1786,1793 ----
  grubd		3136/udp   #Grub Server Port
  iscsi-target	3260/tcp   # iSCSI port
  iscsi-target	3260/udp   # iSCSI port
+ ups-nut	3305/udp   #UPS power local/share/doc/nut/README < ports/sysutils/nut
+ ups-nut	3305/tcp   #UPS power local/share/doc/nut/README < ports/sysutils/nut
  mysql		3306/tcp   #MySQL
  mysql		3306/udp   #MySQL
  ms-wbt-server	3389/tcp   rdp #MS WBT Server